One of the primary arguments made for investing in bus rapid transit (BRT) is that such systems can be implemented not only more cheaply, but also with more ease, than rail lines.

A look at the situation in Nashville suggests that there are limitations to that “ease.”

Much like in cities across the country, residents of Nashville have strenuously debated the merits of investing in a 7.1-mile, $174 million BRT line called the Amp. The project would link the city’s east and west sides, running from the Five Points in East Nashville through downtown to St. Thomas Hospital, past the city’s West End. With dedicated lanes along 80% of its route, frequent service, pre-paid boarding, level platforms, transit signal priority, and an improved streetscape to boot, the line could potentially serve about 5,000 rides a day, double the

Public transportation in Middle Tennessee, in other words, is not big business.

No surprise, perhaps, considering that the City of Nashville has a density of 1,230 people per square mile. By comparison, Portland, Oregon has a concentration population roughly four times as intense. New York City, at the extreme, is 22